230 likes | 712 Views
Identification, Symptoms and nature of damage: Minor pest . Leaf Webber Slug caterpillar Red ants. Identification, Symptoms and nature of damage of mango leaf webber (Lepidoptera: Pyralida ) . End. Previous. Next. Mango Leaf Webber, Orthaga euadrusalis.
E N D
Identification, Symptoms and nature of damage: Minor pest • Leaf Webber • Slug caterpillar • Red ants
Identification, Symptoms and nature of damage of mango leaf webber (Lepidoptera: Pyralida) End Previous Next
Mango Leaf Webber,Orthagaeuadrusalis • Earlier, the leaf webber or “tent caterpillar”, Orthagaeuadrusalis Walker was considered as one of the minor pests of mango • Since last five years it has become a major problem in North India, especially in old, crowded orchards where there is excessive shade. Source:http://www.plantwise.org End Previous Next
Identification • Adult - Brown moth of medium size with wavy lines on fore wings. • Eggs - Eggs are laid in clusters of about ten, on buds and young leaves • Larva - Pale greenish with brown head and prothroacic shield. Fully grown caterpillar measures 2.5 to 3 cm. • Pupa - Pupation takes place in silken cocoons Source: http://www.ikisan.com/Crop%20Specific/ ap_img/brinjal/br_lwdamage.jpg End Previous Next
Symptoms • Leaflets, flowers and pods are held together to form a web by larvae • Larvae feed from inside these webs and give burnt appearance Growth of the terminal shoot is impaired if infested • Infestations may begin as early as seedling stage and continue during flowering and podding • The infestation is severe in shady conditions. • Old orchards with lesser space between tree canopy have more infestation than open orchards. End Previous Next
Nature of Damage • Its infestation starts from the month of April and goes up to December. • Eggs are laid singly or in clusters within silken webbings on leaves. Upon hatching, the caterpillars feed on leaf surface by scrapping. • Later, they make web of tender shoots and leaves together and feed within. • Generally, 1-9 larvae are found in a single web. End Previous Next
Nature of Damage • Pupation takes place inside the webs in silken cocoons. • The life-cycle takes 3-4 weeks • However, the last generation (December-January) pupates in the soil. • The pupae diapause for about five to six months. End Previous Next
Identification, Symptoms and nature of damage of Slug Caterpillar Latoialepida (Lepidoptera: Limacodidae) End Previous Next
Identification • Caterpillar - fleshy and slug like, greenish body with white lines • Four rows of spiny tipped red or black which causes irritation and pain due to glandular secretion. • Adult - green wings with prominent dark patch at the base of each forewing Source: http://www.rakbankerd.com/kaset/Plant/2958_1.jpg End Previous Next
Symptoms of damage • Feed gregariously on the leaves • Cause defoliation – leaving only the midrib and veins End Previous Next
Life Cycle of slug caterpillar • Moth lay eggs flat shining eggs in batches of 20-30 on undersurface of leaves. • The caterpillars feedon leaves. The full grown larva is 2.5 mm approximately. Larva possesses spines which cause irritation and pain if touched. • Pupation takes place on stem in compact elliptical cocoon. End Previous Next
Nest of ants on mango tree Identification, Symptoms and nature of damage of Red Ants (Hymenoptera :Formicidae) End Previous Next
Red Ant, Oecophyllasmaragdina Identification • The wingless ants or the workers measuring 1.2 cm long • Resembles house hold ants, but they are slightly longer • The workers are orangish red in colour • The male and female ants are greenish in colour End Previous Next
Life Cycle • A colony of ants has • one queen • Number of soldiers • Two kinds of workers • Eggs, larvae and pupa housed separately • Eggs are covered with mucilage. Incubation period: 4-8 days • Three larval instars: 10-17 days • Pupal Period: 5-7 days • Life cycle is completed in 20-30 days • They store no food material except some coccids and aphids, whose honey-dew secretion the relish. • These are somewhat dynamic in that they may grow, or move when leaves die. http://www.myrmecos.net/formicinae End Previous Next
Nature of Damage/Control • The ants stitch together few leaves and build their nests in them on the trees • The ants do not cause any direct injury or loss to the tree. • Indirectly, the damage is caused by protecting aphids and scale insects from being preyed upon by their parasitoids and predators and also carries the nymphs of aphids, mealy bugs and scale insects from tree to tree thus spreading the infection of these noxious pests. • These ants aggressively defend "nests" and trees and, whilst they do not sting, chemicals in the saliva can irritate the skin. • They cause annoyance and make harvesting difficult. End Previous Next
Red Ant, Oecophyllasmaragdina As Bio-control agent They also feed other insect pests and can be used in IPM for controlling other pests End Previous Next
Summary • Leaf webbers are active from Dec-April. Larvae webs the leaves and scrape the chlorophyll that results in drying and withering of leaves. Pupation trakes place inside the web • Slug Caterpillar are fleshy and slug like, greenish body with rows of spiny tipped red or black hairs which causes irritation and pain due to glandular secretion. They Feed gregariously on the leaves, cause defoliation • Weaver ants/red ants stitch together few leaves and build their nests in them on the trees. They cause annoyance and make harvesting difficult. • Red ants also feed other insect pests and can be used in IPM for controlling other pests End Previous Next